全文获取类型
收费全文 | 168篇 |
免费 | 14篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 2篇 |
基础医学 | 30篇 |
口腔科学 | 1篇 |
临床医学 | 8篇 |
内科学 | 13篇 |
皮肤病学 | 1篇 |
神经病学 | 86篇 |
外科学 | 3篇 |
综合类 | 9篇 |
预防医学 | 1篇 |
药学 | 17篇 |
中国医学 | 4篇 |
肿瘤学 | 11篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 6篇 |
2014年 | 15篇 |
2013年 | 4篇 |
2012年 | 13篇 |
2011年 | 10篇 |
2010年 | 9篇 |
2009年 | 8篇 |
2008年 | 6篇 |
2007年 | 3篇 |
2006年 | 13篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
排序方式: 共有187条查询结果,搜索用时 15 毫秒
61.
62.
The 1-phenyl-3-methyl-5-pyrazolone (PMP) method has many advantages over hitherto reported methods based on reductive amination and hydrazone formation. This short review summarizes the various aspects of the PMP method, including the principle of derivatization, the simplicity of derivatization procedure, the high sensitivities to UV monitoring and ESI-MS, and the diversity of separation modes in capillary electrophoresis, and presents a number of application data for carbohydrate analysis in biological samples by this method. It also describes successful automation of carbohydrate analysis by in-capillary derivatization with PMP and miniaturization to microchip electrophoresis with whole channel UV detection allowing rapid (within 1 min) analysis of small amounts of PMP derivatives of carbohydrates. Furthermore, it discusses the possibility of capillary electrochromatography in carbohydrate analysis as PMP derivatives, and proposes an in-capillary modification strategy for improving column efficiency and elution time reproducibility. 相似文献
63.
柱前衍生化HPLC法测定黄河滩枣多糖的单糖组成 总被引:1,自引:0,他引:1
目的建立PMP(1-苯基-3-甲基-5-吡唑啉酮)柱前衍生化HPLC法测定黄河滩枣多糖的单糖组成。方法采用水提醇沉法提取黄河滩枣多糖,多糖水解后进行PMP衍生化,HPLC法测定黄河滩枣多糖的单糖组成及摩尔比,并对等度和梯度洗脱两种模式的测定结果进行分析比较。结果黄河滩枣多糖由D-甘露糖、L-鼠李糖、D-半乳糖醛酸、D-葡萄糖、D-半乳糖、L-阿拉伯糖等六种单糖组成,它们的摩尔比约为0.54∶0.50∶0.27∶2.03∶5.40∶1.00,等度和梯度洗脱测定结果基本一致。结论本实验改进的等度洗脱方式更加简便易行,快速准确,适用于黄河滩枣多糖的单糖组成分析。 相似文献
64.
目的 探讨PMP22和TGF-β1在胃癌中的表达及意义。方法 应用免疫组织化学方法检测58例胃癌中TGF-β1和PMP22的表达。结果 在58例胃癌组织中PMP22表达阳性27例(46.6%),其在正常胃组织中亦有表达。PMP22表达与分化程度,分期,分型及淋巴结转移有关。46例TGF-β1表达阳性率为79.3%,TGF-β1表达与分化程度,分期及分型有关,而与淋巴结转移无关。随着胃癌恶性程度的增强PMP22表达逐渐减弱,TGF-β1表达有不同程度的增强。PMP22和TGF-β1的表达呈负相关。结论 PMP22的低表达和TGF-β1的高表达可能与胃癌的恶性转化和增殖有关,可作为反映胃癌生物学行为的指标之一。 相似文献
65.
Lepidopteran insects constitute one of the largest fractions of animals on earth, but are considered pests in their relationship with man. Key to the success of this order of insects is its ability to digest food and absorb nutrition, which takes place in the midgut. Because environmental microorganisms can easily enter Lepidopteran guts during feeding, the innate immune response guards against pathogenic bacteria, virus and microsporidia that can be devoured with food. Gut immune responses are complicated by both resident gut microbiota and the surrounding peritrophic membrane and are distinct from immune responses in the body cavity, which depend on the function of the fat body and hemocytes. Due to their relevance to agricultural production, studies of Lepidopteran insect midgut and immunity are receiving more attention, and here we summarize gut structures and functions, and discuss how these confer immunity against different microorganisms. It is expected that increased knowledge of Lepidopteran gut immunity may be utilized for pest biological control in the future. 相似文献
66.
67.
There are two major sources of cholinergic projections in the brain. The nucleus basalis of Meynert provides the principal cholinergic input of the cortical mantle and the pedunculopontine nucleus–laterodorsal tegmental complex (PPN–LDTC; hereafter referred to as PPN) provides the major cholinergic input to the thalamus. Cortical cholinergic denervation has previously been shown to be part of Alzheimer and parkinsonian dementia but there is less information about subcortical thalamic cholinergic denervation. We investigated thalamic cholinergic afferent integrity by measuring PPN–Thalamic (PPN–Thal) acetylcholinesterase (AChE) activity via PET imaging in Alzheimer (AD), Parkinson disease without dementia (PD), Parkinson disease with dementia (PDD) and dementia with Lewy bodies (DLB). AD (n = 13; mean age 75.4 ± 5.5), PD (n = 11; age 71.4 ± 6.4), PDD (n = 6; age 70.8 ± 4.7), DLB (n = 6; age 68.0 ± 8.6) and normal controls (NC; n = 14; age 69.0 ± 7.5) subjects underwent AChE [11C]-methyl-4-piperidinyl propionate (PMP) PET imaging. PPN–Thal PET data were analyzed using the Nagatsuka method. There were no significant differences in mean age between the groups (F = 1.86, p = 0.134). Kruskal–Wallis testing demonstrated a significant group effect for PPN–Thal AChE hydrolysis rates (F = 9.62, p < 0.0001). Compared to NC, reduced thalamic k3 hydrolysis rate was noted in subjects with PDD (−19.8%; AChE k3 hydrolysis rates 0.1072 ± 0.0143 min−1), DLB (−17.4%; 0.1103 ± 0.0112 min−1) and PD (−12.8%; 0.1165 ± 0.0114 min−1). Each of these 3 subgroups was statistically different from AD subjects (−0.7%; 0.1326 ± 0.0095 min−1) who showed relatively spared thalamic k3 hydrolysis rates which were comparable to NC (0.1336 ± 0.0142 min−1). Thalamic cholinergic denervation is present in PD, PDD, and DLB but not in AD. Neurodegenerative involvement of thalamic cholinergic afferent projections may contribute to disease-specific motor and cognitive abnormalities. 相似文献
68.
Xu J Guan J Chen XJ Zhao J Li SP 《Journal of pharmaceutical and biomedical analysis》2011,55(5):977-983
Multiple species of Dendrobium are widely used as Shihu, a well known Chinese herb, for medicinal purpose in China. Small molecules such as phenols, alkaloids and coumarins are obviously varied in different species of Dendrobium. But there are few reports on polysaccharides, one of major active components, from Dendrobium. In this study, polysaccharides from different species or locations of Dendrobium were compared using saccharide mapping. The results showed that polysaccharides of Dendrobium from different species or locations were obviously varied in spite of they had some similar characters, which is helpful to control the quality of Dendrobium. 相似文献
69.
目的:探索白介素-11对大鼠雪旺细胞分泌髓鞘蛋白的调节作用及相关机制。方法:取成年Wistar大鼠坐骨神经,分离纯化培养雪旺细胞。加入重组大鼠白介素-11,分别采用realtime RT-qPCR和Western boltting检测雪旺细胞髓鞘蛋白的表达情况,进一步检测IL-11调控髓鞘蛋白表达的相关通路的激活情况。结果:Realtime RT-qPCR和Western boltting结果均提示白介素-11可以显著提高雪旺细胞中周围神经髓鞘蛋白22的表达水平,而对雪旺细胞中髓鞘碱性蛋白和髓鞘蛋白零的表达水平则没无明显影响,该生理作用可被JAK特异性抑制剂AG490所抑制。在经过IL-11处理的SCs 细胞中可以观察到pJAK2(Y1007+Y1008)和pSTAT3(Y705)含量明显高于对照组且伴随着SCs中gp130表达的上调。结论:白介素-11可通过调剂gp30/JAK2/STAT3信号通路以促进雪旺细胞中周围神经髓鞘蛋白22的表达。 相似文献
70.
Tomohiro Takeda Hideaki Morita Hirohisa Saito Kenji Matsumoto Akio Matsuda 《Allergology international》2018,67(3):326-333
Platelets play an essential role in hemostasis to minimize blood loss due to traumatic injury. In addition, they contain various immune-associated molecules and contribute to immunological barrier formation at sites of vascular injury, thereby protecting against invading pathogens. Platelets are also crucially involved in development of allergic diseases, including bronchial asthma. Platelets in asthmatics are more activated than those in healthy individuals. By using a murine asthma model, platelets were shown to be actively involved in progression of the disease, including in airway eosinophilia and airway remodeling. In the asthmatic airway, pathological microvascular angiogenesis, a component of airway remodeling, is commonly observed, and the degree of abnormality is significantly associated with disease severity. Therefore, in order to repair the newly formed and structurally fragile blood vessels under inflammatory conditions, platelets may be continuously activated in asthmatics. Importantly, platelets constitutively express IL-33 protein, an alarmin cytokine that is essential for development of bronchial asthma. Meanwhile, the concept of development of allergic diseases has recently changed dramatically, and allergy researchers now share a belief in the centrality of epithelial barrier functions. In particular, IL-33 released from epithelial barrier tissue at sites of eczema can activate the antigen-non-specific innate immune system as an alarmin that is believed to be necessary for subsequent antigen-specific acquired immunological responses. From this perspective, we propose in this review a possible mechanism for how activated platelets act as an alarmin in development of bronchial asthma. 相似文献